Determine the mortality of workers exposed to formaldehyde, with particular attention to detection of increased risk of mortality from malignant neoplasms. A cohort mortality study will develop summary, as well as age, race, and sex specific mortality rates for various causes of death among persons with occupational exposure to formaldehyde for comparison with rates in the general U.S. population. The cohort will be developed from company records and supplemented by pertinant information from other sources, such as Unions and Government agencies.